摘要
13个籼稻杂交组合的研究表明,垩白差异较大的亲本间,其正反交F_1的垩白度存在显著差异,以垩白度较低的品种作母本,其垩白度较低,3个杂交组合分离世代群体中,垩白与百粒重及谷粒宽呈极显著正相关,与谷粒长、谷粒长宽比以及出糙率呈显著或极显著负相关,F_2群体中出现大量正向超亲(高于高垩白亲本)的变异.以垩白度较高的材料作母本回交改良垩白度的效率较低,垩白度具有中等大小的广义遗传率.不同组合中亲本垩白度的差异分别由显性方向不同的1～3组部分显性的基因所控制,要改良稻米垩白,应选择垩白度较低的材料作母本,同时扩大分离世代的种植群体,提高选择强度.
The F1 plants from 13 reciprocal crosses showed significant differences in chalkiness of rice Kermis when the parental difference reached a certain extent, and kernels pro luced by an F1 plant were less chalky when the female parent was less chalky. In the segregating populations, chalkincss of kernels was frequently correlated positively to 100 grain weight and grain width, and nagetivcly to grain length, the ratio of grain length to width and percentage of brown rice. A number of variants exceeding higher parent in chalkincss were found in 3 F2 populations. Backcrossing might have low efficiency in improving chalkiness when higher chalky parent was used as female.Estimates of broad sense heritability of clialkiness were moderate in 3 crosses. Chalky differences between female and male in 3 crosses were controlled, respectively, by 1 to 3 groups of incompletely dominant genes with different overall dominant directions showed by their potence ratios. It is possible to improve chalkiness of rice kernels by using less chalky varieties as the female parent, enlarging F2 population and increasing the intensity of selection.
关键词
籼稻
品质
垩白
遗传
相关
Indica rice ( Oryza sativa L.sp. indica )
grain quality
chalkiness
inheritance
correlation
